Stripe rust of wheat takes its name from the appearance of yellow-colored stripes produced parallel along the venations of each leaf blade. These yellow stripes are characteristic of uredinia that produce yellow-colored urediniospores. The first sign of stripe rust is the appearance of yellow streaks (pre-pustules), followed by small, bright yellow, elongated uredial pustules arranged in conspicuous rows on the leaves, leaf sheaths, glumes, and awns. Mature pustules will break open and release yellow-orange masses of urediniospores. In some varieties, long, narrow yellow stripes will develop on leaves. The infected tissues may become brown and dry as the plant matures or becomes stressed. Severe early infection can result in plant stunting. The disease usually occurs early in the growth season, when temperature ranges between 2 and 15 ℃; but it may occur to a maximum of 23 ℃. High humidity and rainfall are favorable conditions for increasing the infection on both leaf blade and leaf sheath, even on spikes when in epidemic form.